【C#】上机实验九

1. 设计一个Windows登陆窗体应用程序，能够实现根据现有表中数据模拟登陆，并设置相关属性，具体界面如下。

可能使用到的类：

（1）SqlConnection

（2）SqlCommand

（3）SqlDataReader

（4）MessageBox

---

 using System;
 using System.Collections.Generic;
 using System.ComponentModel;
 using System.Data;
 using System.Drawing;
 using System.Linq;
 using System.Text;
 using System.Windows.Forms;
 using System.Data.SqlClient;

 namespace Myform
 {
     public partial class Form1 : Form
     {
         public Form1()
         {
             InitializeComponent();
         }

         private void label1_Click(object sender, EventArgs e)
         {

         }

         private void button1_Click(object sender, EventArgs e)
         {

             string connString = @"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=D:\C#09J20172202899何海钊\Myform\Myform\Properties\Database1.mdf;Integrated Security=True";
             SqlConnection conn = null;
             SqlCommand cmd = null;
             SqlDataReader reader = null;
             try
             {
                 conn = new SqlConnection(connString);
                 conn.Open();
                 cmd = conn.CreateCommand();
                 cmd.CommandText = "Select username , password From Table1 where username = @username and password = @password ";
                 cmd.Parameters.AddWithValue("@username", textBox1.Text.Trim());
                 cmd.Parameters.AddWithValue("@password", textBox2.Text.Trim());
                 reader = cmd.ExecuteReader();
                 if (reader.Read())
                 {
                     MessageBox.Show("登录成功", "OK", MessageBoxButtons.OK, MessageBoxIcon.Information);
                 }
                 else
                 {
                     MessageBox.Show("用户名密码不正确", "NO", MessageBoxButtons.OK, MessageBoxIcon.Error);
                 }

             }
             catch (Exception ex)
             {
                 MessageBox.Show(ex.Message, "Open Error", MessageBoxButtons.OK);
             }
             finally
             {
                 if (reader != null) reader.Close();
                 if (conn.State == ConnectionState.Open) conn.Close();
             }
         }
     }
 }

Code1

2、设计一个Windows登陆窗体应用程序，根据下图设置相关属性，该程序能够读写现有表中数据，具体界面如下。

 using System;
 using System.Collections.Generic;
 using System.ComponentModel;
 using System.Data;
 using System.Drawing;
 using System.Linq;
 using System.Text;
 using System.Windows.Forms;
 using System.Data.SqlClient;

 namespace Myform2
 {
     public partial class Form1 : Form
     {
         public Form1()
         {
             InitializeComponent();
         }

         private SqlConnection conn = null;
         private SqlCommand cmd = null;
         private SqlDataReader reader = null;
         private SqlDataAdapter adapter = null;
         private DataSet List = null;

         private string connString = @"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=D:\C#09J20172202899何海钊\db\Database1.mdf;Integrated Security=True;Connect Timeout=30";

         private void button1_Click(object sender, EventArgs e)
         {
             try
             {
                 conn = new SqlConnection(connString);
                 conn.Open();
                 cmd = conn.CreateCommand();
                 cmd.CommandText = "Insert into Table1 ( username , password ) values (@username , @password ) ";
                 cmd.Parameters.AddWithValue("@username", textBox1.Text.Trim());
                 cmd.Parameters.AddWithValue("@password", textBox2.Text.Trim());
                 int n = cmd.ExecuteNonQuery();
                 if ( n >  )
                 {
                     MessageBox.Show("成功插入", "Insert OK ", MessageBoxButtons.OK, MessageBoxIcon.Information);
                 }
                 else
                 {
                     MessageBox.Show("插入失败", "Insert error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                 }

             }
             catch (Exception ex)
             {
                 MessageBox.Show(ex.Message, "Open Error", MessageBoxButtons.OK);
             }
             finally
             {
                 if (reader != null) reader.Close();
                 if (conn.State == ConnectionState.Open) conn.Close();
             }
         }

         private void button2_Click(object sender, EventArgs e)
         {
             try
             {
                 conn = new SqlConnection(connString);
                 conn.Open();
                 cmd = conn.CreateCommand();
                 cmd.CommandText = "Select * From Table1 ";

                 adapter = new SqlDataAdapter(cmd);

                 List = new DataSet();

                 adapter.Fill(List);
                 DataTable table = List.Tables[];

                 DataRowCollection Rows = table.Rows;

                 for (int i = ; i < Rows.Count; i++)
                 {
                     DataRow row = Rows[i];
                     string username = (string)row["username"];
                     string password = (string)row["password"];

                     this.richTextBox1.Text += username + " " + password + "\r\n";
                 }
             }
             catch (Exception ex)
             {
                 MessageBox.Show(ex.Message, "Open Error", MessageBoxButtons.OK);
             }
             finally
             {
                 if (reader != null) reader.Close();
                 if (conn.State == ConnectionState.Open) conn.Close();
             }
         }
     }
 }

Code2

---

3、设计一个Windows窗体应用程序，根据下图设置相关属性，该程序能够读取AdventureWorksDW_Data.mdf数据库中DimReseller表中数据，具体界面如下。

 using System;
 using System.Collections.Generic;
 using System.ComponentModel;
 using System.Data;
 using System.Drawing;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 using System.Windows.Forms;
 using System.Data.SqlClient;

 namespace FormPage
 {
     public partial class Form1 : Form
     {

         private SqlConnection conn = null;
         private SqlCommand cmd = null;
         private SqlDataAdapter adapter = null;
         private SqlDataReader reader = null;
         private DataSet ds = null;

         private int pageSize = ;
         private int rowCount = ;
         private int pageNum = ;
         private string connectString = @"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=D:\C#09J20172202899何海钊\MyForm3\AdventureWorksDW2008\AdventureWorksDW_Data.mdf;Integrated Security=True;Connect Timeout=30";

         public Form1()
         {
             InitializeComponent();
             Count_Row();
             Fill_Data();
         }

         private void btn_FirstPage_Click(object sender, EventArgs e)
         {
             pageNum = ;
             Fill_Data();
         }

         private void btn_LastPage_Click(object sender, EventArgs e)
         {
             pageNum = rowCount/pageSize;
             Fill_Data();
         }

         private void btn_PrePage_Click(object sender, EventArgs e)
         {
             if( pageNum >  )
             {
                 pageNum--;
                 Fill_Data();
             }
         }

         private void btn_NextPage_Click(object sender, EventArgs e)
         {
             if (pageNum < rowCount / pageSize)
             {
                 pageNum++;
                 Fill_Data();
             }

         }
         private void btn_Fill_Click(object sender, EventArgs e)
         {
             Fill_Data();
         }
         void Fill_Data()
         {
             if (pageNum == )
             {
                 btn_FirstPage.Enabled = false;
                 btn_PrePage.Enabled = false;
             }
             else
             {
                 btn_FirstPage.Enabled = true;
                 btn_PrePage.Enabled = true;
             }

             if( pageNum == rowCount / pageSize)
             {
                 btn_LastPage.Enabled = false;
                 btn_NextPage.Enabled = false;
             }
             else
             {
                 btn_LastPage.Enabled = true;
                 btn_NextPage.Enabled = true;
             }
             try
             {
                 conn = new SqlConnection(connectString);
                 conn.Open();

                 cmd = conn.CreateCommand();
                 cmd.CommandText = "Select top ("+pageSize+ ") Employeekey , FirstName , LastName , EmailAddress , Phone from DimEmployee where EmployeeKey not in( Select top (" + pageSize *pageNum+ ") EmployeeKey from DimEmployee order by EmployeeKey ) order by EmployeeKey";

                 ds = new DataSet();
                 adapter = new SqlDataAdapter(cmd);
                 adapter.Fill(ds , "DimEmployee" );

                 dataGridView1.DataSource = ds;
                 dataGridView1.DataMember = "DimEmployee";

             }
             catch (Exception ex)
             {
                 MessageBox.Show(ex.Message, "Fill Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
             }
             finally
             {
                 if (conn.State == ConnectionState.Open)
                     conn.Close();
             }
         }

         void Count_Row()
         {
             try
             {
                 conn = new SqlConnection(connectString);
                 conn.Open();

                 cmd = conn.CreateCommand();
                 cmd.CommandText = "Select count(*) from DimEmployee";

                 reader = cmd.ExecuteReader();
                 if( reader.Read())
                 {
                     rowCount = reader.GetInt32();
                 }
                 else
                 {
                     MessageBox.Show("Search Error", "0 row", MessageBoxButtons.OK, MessageBoxIcon.Error);
                 }
                 if (reader.IsClosed)
                     reader.Close();
             }
             catch (Exception ex)
             {
                 MessageBox.Show(ex.Message, "Search Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
             }
             finally
             {
                 if (conn.State == ConnectionState.Open)
                     conn.Close();
                 if( reader.IsClosed)
                     reader.Close();
             }
         }
     }
 }

Code3